I started a shell off restoration a couple weeks ago on a 1979 28'. It was the first Airstream my grandfather ever sold when he started working as th GM at the now gone AS dealer in New Orleans.

Anyway, i have the shell off and before i pulled the floor and started my metal repair i used the old floor to pattern new pressure treated plywood. Since there was some plywood rotted away i used the best corner on the front to to help fill in a gap in the radius on the other side. Both front corners proved to be identical. When i got to the back i started with the best corner and cut it. When i took the drop and placed it on the other side to fill in the missing radius i dicovered it was drastically different. The street side rear corner had a smaller radius or was pulled in a good 1.5 inches. All the steel, aluminum, and plywood are all original so it appears to have left the factory this way.

I would guess all plywood is cut from a jig at the plant. It seems very strange that the two rear corners were cut so different. I was curious if anyone had ever run across this. I would imagine many may pattern and never compare but was wondering if anyone else had seen the same thing.

you would never use PT wood inside your house would you? PT plywood is very unstable, not flat, full of voids, and varies drastically in thickness over the sheet. The way it reacts with aluminum is just one of many reasons why not to use it.